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When does difference in sample size become an issue?

  1. Mar 7, 2012 #1
    I was comparing two different groups, and in one, my n was 1600, and the other n was around 700. I found pretty much all significant differences, but is that maybe due to sample size. I tried doing a random selection making the sample sizes equal (both around 700) and got more or less the same numbers and significance every time. Should I do anything else, or is this fine?
    I also bootstrapped within one of these restricted sets and got about the same numbers.
     
  2. jcsd
  3. Mar 8, 2012 #2
    Do you need help checking distribution type by plotting it?

    I am doing a plotting program to look at data-sets and check for normal-ness,
    if you'd like, & your data is "near" normal -- you can attach a text file with the data (or a scaled version of it...to obscure what it is) that just lists the data values. eg:
    7
    3.5
    11.0

    etc;
    And I could plot the data into 1% or 0.05% quantiles; like this:
    converting binomial/normal distribution into quantiles and comparing against normal
    and then I could post the graphs for you... :smile:
    It will show skewness, and some information that could help identify what type of distribution it really is, but it's mostly to check Gaussian data...
     
    Last edited: Mar 8, 2012
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